Abstract: Objective To explore the effect of phoxmi on the prolife ration of mouse bone marrow cells.Methods Phoxmi was administrated to miceat doses of 160,80,40,and 20 mg/kg·bw once by gavage.Then the changes of cell proliferation index were detected by cytogenetic method 24 hours after the intragastric admin istration.Results The cell proliferation indexes of mice marrow were 3.16%,3.68%,and 4.70%,respectively,corresponding to 160,80 and 40 mg/kg·bw doses of phoxmitest group with the decreased index values of 47.33%,38.67%,and 21.67% compared with that of the negative control(6.00%),and the diffe rence was statistically significant(P<0.001).The cell proliferation index (2.71%)of male mice were significantly lower than that of female mice(3.61%)(P<0.05).The cell proliferation index was 6.07% at the dose of 20 mg/kg·bw and there was no significant change(P>0.05) compared with that of the negative control group.Conclusion Phoxim can inhibit proliferation of mousemarrow cells at relative high dose and the effect on male miceis stronger than that of on female mice.